Methylsilsesquioxanes (MSQs) are synthetic materials with a empirical formula of (CH3SiO3/2)n. They are generally prepared by hydrolysis and condensation of precursors such as CH3SiX3, where X is generally Cl, OCH3 (methyltrimethoxysilane (MTMS)) or OC2H5 (methyltriethoxysilane (MTES)).1-3 They have long been used in a wide variety of applications such as insulating coatings for optical and electrical devices,1 and as additive powders to materials such as cosmetics, polypropylene films, and methacrylic resins.2 Recently, MSQ has been used as a low k dielectric material in the semiconductor industry to minimize resistance-capacitance delay.4 The newest and potentially largest-scale application of MSQ is as monolithic columns for normal and reversed-phase chromatography. Nakanishi et al. showed that bicontinuous macroporous MSQ-based columns prepared under highly acidic conditions have no shrinkage in capillaries up to an i.d. of 0.5 mm and a theoretical plate number as large as 100,000 when operated in the normal phase mode.5 MSQ displays exceptional properties toward polar solvents and has a water contact angle larger than 150°,6 and thus so-called “superhydrophobic” materials have received a lot of attention by many research groups recently.7 MSQ is also the primary material used for entrapment of lipases as biocatalysts, due to its hydrophobicity. In this application, MTMS is often co-condensed with tetraethoxysilane (TEOS) and tetramethoxysilane (TMOS) to form hybrid matrixes.8 
Previous studies have greatly increased understanding of the sol-gel chemistry of MTMS9-11 and MTES,12 and the structure-property relationships of MSQ.4,6,11,13 Most of these investigations are focused on how to synthesize stable MSQ sols11 and/or on the properties of dense or slightly porous thin films.6,11 Generally speaking, gelation of MTMS and MTES is much more difficult than TEOS and TMOS due to extensive cyclization under acidic conditions,9,12 premature phase separation over a broad pH range,14 and fewer functional groups for cross-linking. Loy and co-workers concluded that it was not possible to prepare MSQ gels except at extremely high or low pH regardless of monomer or water concentration.15 Consequently, there are only a few reports that describe porous MSQ gels6,14 and many of their properties, such as pH stability and morphology, are still elusive. Also, processing at extreme pH values makes it difficult to employ pure MSQ materials for applications such as protein entrapment.
There remains a need for improved processing methods to form monolithic MSQ materials that will provide better control over the morphology and shrinkage properties of the final material. There is also a need to examine how such materials perform as chromatographic stationary phases and as supports for protein entrapment.